code: def test_multi_agent_invalid_args(self):
      self.assertRaisesRegex(
          TypeError,
          "got an unexpected keyword argument 'wrong_key'",
          lambda: (
              PPOConfig().multi_agent(
                  policies={"p0"}, policies_to_train=["p0"], wrong_key=1
              )
          ),
      )
  
file_path: ray/python/ray/rllib/utils/tests/test_check_multi_agent.py
imports: import unittest
  from ray.rllib.algorithms.ppo import PPOConfig
  from ray.rllib.policy.policy import PolicySpec
label_desc: Use image node_id 1 for calling the TestCheckMultiAgent obj's underlying member method code with example usage: obj.test_multi_agent_invalid_args() without return types